British Scientists Reverse Casimir Effect 347
An anonymous reader writes "The Telegraph reports that Scientists at the University of St. Andrews have developed a technique to cause the Casimir effect to repel instead of attract. This discovery could lead to near frictionless machines or in theory even levitation."
wait... (Score:4, Insightful)
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Re:wait... (Score:5, Funny)
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No - the technique is nothing more than concentrated Republican extract.
Re:wait... (Score:4, Funny)
Re:wait... (Score:5, Funny)
That depends on who is defining "world".
Oh no! (Score:5, Funny)
uplifting (Score:3, Funny)
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Re:uplifting (Score:5, Funny)
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http://en.wikipedia.org/wiki/Uplift_Universe [wikipedia.org]
Repeal instead of attract. (Score:5, Funny)
casmir (Score:5, Funny)
Re:casmir (Score:5, Funny)
Hmm (Score:2, Funny)
You heard it hear first, on slashdot.
miniature giant space hamsters (Score:3, Funny)
Given that the Casimir effect actually produces enough force (well, pressure) at tens of nanometres distances between the two plates, that'll be some really tiny giant mecha
Finally... (Score:2, Funny)
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repeal vs. repel (Score:4, Informative)
They'd better be careful (Score:2, Insightful)
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Probably. Many major scientific breakthroughs have come from researchers working on weapons technology. And vice-versa -- many new weapons technologies have come from researchers working on scientific breakthroughs.
Imagine causing all of the atoms in a tank to repel each other. Messy.
Re: (Score:2)
Step 1: Weaponize Casimir reverser
Step 2: Figure out how much money to demand from the world governments so you don't use the weapon
Step 3: Profit!
Re:They'd better be careful (Score:5, Informative)
In the quantum description of the electromagnetic field, there is no such thing as uniformly zero field - even in completely empty space, there are oscilations in the field spread over all modes (ie. wavelengths). It can be compared to an ocean or pond in stormy weather where there will allways be *some* waves.
Now, if we have a geometry consisting of two flat opposing plates, only certain wavelengths corresponding to the distance between the plates will be allowed. Thus by increasing or decreasing the distance between the plates, we can deside which zero-point wavelengths will be allowed, and it is such that the situation where the plates are very close are energetically favorable, hence we will see the two plates attract each other and this is known as the casimir force which has been measured many times in the experiment. Its important to realize that its not charges on the plates which are doing the work - everything is kept charge neutral. Its vacuum doing work
(by manipulating the geometry of the plates, inserting lences, etc. its then theoretically possible to make the plates repel instead, which is what the article is about)
Anyway. My point is. This is not like nuclear chain reactions. The experimental conditions under which you see these effects are extreme (as in: the truck on the street or the cellphone in the assistants pocket will ruin it). Its a neat discovery, but the doom and gloom is completely uncalled for.
I'll be impressed... (Score:2)
Using the force? (Score:5, Funny)
So was it only me that heard Sir Alec Guinness read that line out?
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In actual fact it's Sir Alec, if he was a Lord it would be Lord Guiness and if he was a King it would be King Alec.
Not a high point in science journalism (Score:4, Informative)
Re:Not a high point in science journalism (Score:5, Funny)
I assure you, Ladies and Gentlemen of the audience, this gigantic crate is levitating! Between it and the stage are entire nanometers of magic.
And the Casimir effect is... (Score:5, Informative)
Doesn't sound useful on a large scale (Score:3, Insightful)
A standard solution for a 'frictionless bearing' is an air bearing. http://en.wikipedia.org/wiki/Air_bearing [wikipedia.org]
The utility of this work seems limited to very small things.
the Force (Score:2)
a.k.a. "the Force"
Requires a perfect lens (Score:5, Informative)
According to the researchers, the negative-index metamaterial is able to modify the zero-point oscillations in the gap between the surfaces, reversing the direction of the Casimir force. Indeed, the researchers believe that this repulsive force is strong enough to levitate an aluminium mirror that is 500nm thick, causing it to hover above a perfect lens placed over a conducting plate. Since the Casimir force acts on the length scale of nanomachines, manipulating it could be important for future applications of nanotechnology.
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Reminds me of the brilliant proof for the existence of perpetual motion machines, that assumes a magnetic monopole.
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Just in case... you saw it here first
Cheers!
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Negative refractive index materials have already been demonstrated, for specfic wavelengths. Haven't managed on visual wavelengths yet, as far as I can remember.
Re:Requires a perfect lens (Score:4, Interesting)
huh? (Score:5, Funny)
Sheesh. Anybody would think
oh..
Re:huh? (Score:5, Funny)
Re:huh? (Score:5, Funny)
AI did not know that. AI'm glad you were here to point that out!
Abye.
APS:, AWhy didn't your sentence start with a capital A?
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Yes, ha ha. But just so people don't get the wrong idea, apodyopsis wasn't starting a new sentence, but rather was using a question mark mid-sentence, which is perfectly allowed.
http://en.wikipedia.org/wiki/Question_mark [wikipedia.org]
Dry glue? Are you thinking what I'm thinking? (Score:5, Funny)
"Spider-pig, Spider-pig,
Does whatever a Spider-pig does."
Re: (Score:3, Funny)
"Can he fly from a web?
No he can't 'cause he's a pig"
Re:Dry glue? Are you thinking what I'm thinking? (Score:5, Funny)
Does whatever a Spider-pig does."
"Can he fly from a web?
No he can't 'cause he's a pig"
"Look out! He isn't paper trained....."
*applause* (Score:2, Interesting)
Modulating fields like this seems to me to be some sort of thrusting action although they don't come out and say it.
Well, it's _scheduled_ for publication (Score:3, Informative)
Quantum levitation by left-handed metamaterials
Ulf Leonhardt and Thomas Philbin
Provisionally scheduled for August 2007
Woohoo (Score:2, Funny)
Casimir Scientists' Own Page (Score:5, Informative)
Being British... (Score:4, Insightful)
2. Tell everyone about it
3. ???? 4. NO Profit
It's sad to say that here in the UK we never learn and have a long and distinguished history of brilliant research followed by total fumbling of the ball and making no money out of the discoveries whatsoever.
Re:Being British... (Score:4, Insightful)
Woah, you want to tell me that there are scientists who actually do science for...err...sake of science, not money? What a surprise!
Without irony, I personally don't believe in profiting from BIG discoveries. If you get some applications going from that discovery, then it is understandable that you can and you will profit from them, but not from discovery itself.
Re:Being British... (Score:4, Funny)
Cheers!
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That should be pretty obvious. The moment that you start to make progress on a working Time Machine, something unfortunate and completely unforseen will happen to stop you from finishing it. Maybe you will just decide to paint bubble wrap red and paint the words 'TENSION SHEET' on it instead.
Because somewhere in the future, somebody has got to really hate having his history messed with.
Re:Being British... (Score:4, Informative)
Re:Being British... (Score:5, Insightful)
From the researcher's point of view:
Step 3 doesn't have to involve selling technology.
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That is all.
an almost content-free article (Score:4, Insightful)
The thelegraph is supposed to be one of the more serious british dailies. So heaven help us all if this is what they pass off as a science story.
Casimir... (Score:3, Funny)
Slam Dunk Reporting, Guys (Score:5, Informative)
This wasn't enough for me, so I wandered over to Wikipedia:
The only changes to the Wikipedia article lately have been a link to this article, which is sort of meta. Wikipedia linking to an article plagiarizing from, of all places, Wikipedia. Cute, but also a little sad.
When I hear 'Casimir', I think 'Zero Point'... (Score:5, Interesting)
The Casimir effect happens when you get two surfaces very nearly touching. Virtual particles emerge on the other side of the surfaces and force them together. Virtual particles being, well, virtual -- very short-lived and low-energy -- this effect only occurs when the surfaces are very, very close to one another.
What's intriguing about the Casimir effect is that it is extracting work from the zero point energy of the universe, the base energy field of empty space. (Yes, even a total vacuum contains virtual particles, and thus some energy.) It is not immediately obvious how to make this useful, however, if the only way to tap into the zero point energy is to destructively sandwich two expensive materials together.
Reversing the Casimir effect is brilliant. By placing a perfect lens between the two materials, the virtual particles create a repulsive force. This could, as stated, create a levitation effect by preventing the surfaces from ever touching. 'Levitation' is a strong word, though. It'll 'levitate' a nanometer or so above the other surface, which is only good for reducing the friction between them to zero. So 'frictionless surfaces' is probably the keyword we should be using here.
I'm intrigued because it would seem to be easier to generate power from the zero point energy with a repulsive effect than an attractive one. So this could also be the first step toward a zero point energy generator -- free energy. What will they think of next...
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I'm intrigued because it would seem to be easier to generate power from the zero point energy with a repulsive effect than an attractive one. So this could also be the first step toward a zero point energy generator -- free energy. What will they think of next...
My thoughts exactly, although I found myself unable to word them thusly, which brings us to this inevitable question : Wouldn't it violate the second law of thermodynamics?
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Cheers!
--
Vig
Re:When I hear 'Casimir', I think 'Zero Point'... (Score:5, Informative)
Let me explain further:
Heisenberg's uncertainty principle says you can't know where a particle is, or it's momentum, at the same time. That applies to space too. For any point in space, you can't know if there's a particle there or not.
Therefore, the reality is that the vacuum is boiling all the time with particles popping into and out of existence all the time. Particle soup. For another interesting effect of this, check out Hawking radiation.
Anyway, if the plates are close enough together, no particles can be popping into existence in that space, because it's too small. It's literally small enough that if there were a particle there, you'd know it's position and momentum, and that is NOT allowed.
So, the situation you've set up is that you have two plates very close together, with particles appearing and disappearing on one side of the plates (the outside surfaces) but not on the inside surfaces. That means that there's a pressure created which forces the plates together.
No energy is created because what you're doing is preventing particles (energy) from appearing inside the plates. The energy of a vacuum is not zero because of those particles. The energy inside the plates is zero (zero point energy).
The problem is that once the plates have moved together which is work, you don't get any more work out of the system unless you move the plates back apart.
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That's fine. The non-physicists here will gleefully take up the slack.
From the article (Score:4, Funny)
In Theory (Score:5, Funny)
There, now that I've officially theorized this, I can say, "In theory, cramming peanuts into your arsehole will cause levitation." and it's perfectly true.
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Well, I tested your theory, three times.
And I've documented the effects, three times.
I got the same results every time.
No levitation, but I won't be able to sit down for a week.
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Casimir effect allows geckos to walk on ceiling (Score:5, Funny)
Finally some recognition! (Score:4, Funny)
Re:ummmm? (Score:5, Informative)
Re:ummmm? (Score:5, Informative)
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Re:ummmm? (Score:5, Informative)
http://www.st-andrews.ac.uk/~ulf/levitation.html [st-andrews.ac.uk]
Pity they have a photo of Syndrome and his Zero-Point Energy device as an example at the top. Doesn't help anyone to take them seriously surely.
Re:ummmm? (Score:5, Informative)
http://www.arxiv.org/abs/quant-ph/0608115 [arxiv.org]
It should be noted that this work is purely theoretical. What they have done is show that there is a much more physically realizable way to way a repulsive Casimir effect than the previous schemes, using a material with negative refraction over some range of important frequencies (this is a similar problem as making a cloaking device, but with a harder range of the spectrum). In practice, the effect would be small and the material hard to make, but the idea is interesting.
Re:ummmm? (Score:5, Funny)
I assume it involves a cat with a piece of buttered toast strapped to its back...
Re:ummmm? (Score:5, Funny)
From what I remember of the buttered toast cat, doesn't it end up spinning just above the floor as the cat tries to land feet-first and the toast tries to land butter-side down? If so then why is no-one wrapping these cats in wire, putting them between magnets and throwing them off surfaces en-mass to generate electricity while they spin?
Re:ummmm? (Score:4, Funny)
Re:ummmm? (Score:4, Funny)
Don't worry, that's a cyclic effect that primarily appears when posting AC. In your case, it's probably just your sinuses. No need to go off on a tangent. Have a slice of pie and call me in the morning. I'm sure you're feel radiant by then.
indeed (Score:3, Funny)
Indeed. The power of privacy that comes with being an Alternating Commenter can be electrifying but is sometimes a revolting experience. It's sometimes better to take charge and post directly as your user name instead.
Re: (Score:3, Funny)
Don't they mean Schrödinger's cat? It would simultaneously both produce electric current and not produce it until you touched the wire to find out.
Re:ummmm? (Score:5, Funny)
Re:ummmm? (Score:4, Funny)
Re:ummmm? (Score:4, Funny)
Re:ummmm? (Score:5, Funny)
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Yung Nasteecat use powah of flite [icanhascheezburger.com]
Casimir Effect Explained (Score:5, Informative)
Ok so far but how do we get an attractive force? Well it turns out that charge must be conserved so if one region of space has a small positive charge at one instant a neighbouring area must have a small negative charge (in quantum terms we say that we pair produce and virtual electron-positron pair) thuse we have a dipole. Now remember the two conductors? Well the one nearest the positive charge will have the electrons in the conductor attracted to it and being a conductor they will move towards it giving the conductor a net negative charge. The opposite will happen in the conductor nearest the negative charged area of space.
So now we have, instantaneously, a conductor with a negative charge and one with a positive charge...so they attract one another. this is the Casimir effect. If you stop to think about it is is VERY strange because it means that two metal plates in vacuum, with no externally applied fields will attract...so you have to ask yourself what exactly is doing the work i.e. where is the energy coming from to move these plates?
I'm not a condensed matter guy so I must admit I don't quite understand why this effect is so important to them. I understood that in molecules it was known as Van der Waal forces and due to periodic dipoles occuring in molecules in much the same way it does ina vacuum. Only, because there is a real electric field, the effect is much larger. So if there are any condensed matter people out there perhaps they would like to explain why it is Casimir and not Van der Waals that is important? or is it just because they have the same origin the name Van Der Waals has been dropped?
Mundi est omnis divisa in partes tres (Score:3, Informative)
Re:Casimir Effect Explained (Score:5, Informative)
Also there is actually no evidence whatsoever that gravity and EM fields are interrelated. It is postulated that at around 10^16 GeV they are but there is no evidence for that yet....and just to show you how much faith you should put in theory without concrete evidence to back it up remember that at one time people thought that the Earth was flat!
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Re:Disintegrators (Score:5, Funny)
Okay, that's a good safety tip. Don't cross the streams!
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Finally, I can retrofit the Prius and get it to fly. And screw you guys that want to retrofit your Hummers.
I say we enact a law that will only allow environmentally friendly vehicles to fly. Do it now before Hummers are grandfathered.
Re:I, for one (Score:4, Funny)
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I used to post AC when doing this, but it's just Slashdot. I don't give a shit about my karma anymore. Mod me down all you want.
Re:Repeal? (Score:5, Funny)
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